What is the cheapest I can build a 1/8 brushless buggy?

[R00ST]

Alright so here is the deal... I am an avid RC fan who recently came back to rc. At one point I had 13 rc's (12 electric, and a further 6 brushless lol). My favorite vehicles were my brushless rs4mt (always broke belts) and my brushless E-revo, but it was really heavy (this was long before conversion kits...the good old home made one).

I did buy a rustler off ebay and put an MM controller and Traxxas VXL motor in it. I have two 3s 5000 mah packs. This truck is fun, but I miss 4wd!!!

I was considering doing a brushless buggy converison. What is the cheapest I can accomplish this? Is there a motor I can run with the MM (would rather not buy the MMM...its kinda pricey lol). I used to run a 9920 and 9xl on the e-revo on 14 3800 cells and it ran pretty good.

Can the MM handle a 7XL on 6s? I assume 3s is not enough...?

Since i already have an MM and two 3s packs... I would like to utilize those if possible.

So which buggy is the best/easiest/cheapest to convert?

I searched ebay and found this: http://cgi.ebay.com/Losi-8ight-Buggy...QQcmdZViewItem

Is this a good deal? What else would I need to get it running?

Worse case scenario is I can sell the rustler setup RTR and start fresh, but would prefer not to do this if I can avoid it (cheaply!)

Thanks for any ideas and information!

mike